Been fighting an issue with my car being fairly sluggish for quite some time and may have finally fixed it but wanted to see if anyone else has had this happen.

Basically my setup is:

345
11.5:1
Fully ported X's
275/275 .585/.585 Solid
Hooker Super comps
Fully ported M1 intake
QFT Q-950-AN
Mallory SS 32 and 6AL box
3.91 then 4.30 gears

Basically after putting the engine the first time it never felt right and would absolutely struggle to hit 7k. Took it back apart and with the help of Rob Y. found out the springs were way too weak for this cam even though they were originally the ones called out for. Had the spring issue fixed and had the heads fully ported at this time as well with all the other goodies. Put it all back together and STILL the thing just felt like it was hitting a wall at 1/2 - full throttle. More hours spent on the phone with Rob who graciously put up with my million questions.

Borrowed an LM-1 and the carb was a bit rich but nothing that should have caused this. Finally about had enough over the weekend and took the car to the engine builder who did the heads and after verifying ignition and everything looked at the intake and commented how the plenum went right into the runners. Put a 1" spacer on it with the 4 bore holes and holy smokes it pulls like a freight train now and will hit 7300 instantly.

Has everyone else running this intake had to put spacers on due to the same issue? I always wondered why the indy 360 intake had such a tall plenum and I guess now I know.

Now if I can get the A/F ratio correct (11.5 WOT) I'll be doing even better. It's obvious this 950 is probably way too big for the engine but planning on building a stroker I didn't want to buy two carbs. The car idles around 13.0 A/F but at cruise (60 mph 3400 rpm) it appears that it is running on the transition area at 11.5 - 11.8 A/F. Give it a little throttle and it'll go to 12.2 or so. What is the best thing to clear this up? Currently has 74/78 jets but when I previously went to 70 or 72 in the primaries when I would get into the throttle right before secondaries it would go totally lean around 15 A/F.

Sorry for the long post but feels good to finally be getting close and couldn't have gotten here without moparts members!